The polymer of this invention is a compound which features amine groups in its molecular structure and cannot be directly prepared by terpolymerization. It has long been recognized that the double bonds of many vinylic monomers are highly reactive towards amines (ref.: Hendrickson, Cram & Hammond, "Organic Chemistry, 1970, p. 480) and are, therefore, not stable. For this reason, amine-containing monomers, for the most part, are not available to be used for the preparation of amine-containing polymers.
Cyclic anhydride containing thermoplastic polymers can be reacted with diamines by an imidization process to produce amine functional polymers. Unless extremely large excesses of diamine are used, some crosslinking and gel formation will result. Typically, tenfold excesses of diamine are used to minimize, but not eliminate, crosslinking.
Relevant discussions concerning the kinetics of amic-acid formation and imidization of polymeric and small molecule mixtures measured by Fourier-Transform IR spectroscopy at near ambient and elevated temperatures were disclosed in Kinetics of Amine-Cyclic Anhydride Reactions in Moderately Polar Solutions by Allen R. Padwa et al in Journal of Poly. Science Part A: Polymer Chemistry, Vol 33, 2165-2174 (1995).
Also, the reaction of amine and anhydride functionalities were reported to be sensitive to the environment of the functional group. In accordance with Padwa et al, in Kinetics of Amine-Anhydride Reactions for Reactive Processing, Polymer Preprints 34,2, 841 (1993), extrapolation from low molecular weight chemistry to polymer bound functionalities are not necessarily a sound basis for choice of functionality. Reactive melt-processing of poly(styrene-co-maleic anhydride) with primary amine was reported in an article by Vermeesch et al in Journal of Poly. Science Vol. 63, 1365-1378 (1994).
It is the objective of the present invention to produce amine functional thermoplastic polymers. It is the further objective to describe an extrusion process to efficiently produce said polymers.